The present invention discloses a device and method of use of this device to displace at least one person and more particularly to propel at least one person using skates, skis, wheels, or similar friction reducing means over a variety of terrains.
The prior art discloses several different devices to aid in the displacement of a person when used in conjunction with friction reducing devices such as skis, skates, or wheels. For example, U.S. Pat. No. 4,508,187 (Wenzel) discloses a motorized roller skate apparatus wherein the motor is secured to the back of the user wherein the device comprises a flexible drive leading from the motor to the front wheel truck of a roller skate. Though this device was an improvement over the prior art, see, e.g., U.S. Pat. No. 2,857,008 (Pirrello), this configuration provides limited versatility in only providing propulsion to conventional roller skates. Additionally, this device is limited to providing power to the small front wheel truck of the device. Moreover, this device is not prepared to encounter the varied environments that a user may wish to enjoy. Finally, the creation of thrust on the lowest point of the user can create a balancing problem.
Fan propulsion units have offered another approach. For example, U.S. Pat. No. 4,189,019 (Zech) discloses a backpack style propulsion unit with a variable thrust means. By employing an internal combustion engine integrated with a fan, the device is capable of generating a thrusting force to deploy a user who is utilizing a friction reducing means. Offering an improvement, U.S. Pat. No. 5,222,569 (Martel) discloses a backpack fan assembly that lowers the thrusting point to aid in stability. Unfortunately, even Martel cannot overcome some of the problems with this design. First, the user is burdened with bearing the full weight of either device. This increase in weight effectively increases the burden on the friction reducing devices being used. Additionally, these devices offer less stability than the present invention because slight adjustments in posture or a shifting of the user""s weight can substantially alter the thrusting direction and the line of travel, consequently. Finally, the exclusive use of a fan to propel the user reduces the power and speed that the user may enjoy. As a result, these devices are more limited in providing effective propulsion in less than optimal environments.
Analogously, a few devices have implemented a rear-mounted device to provide propulsion. For example, U.S. Pat. No. 4,175,627 (Husted) discloses a propulsion system for a snow going device comprising a tread having a roller chain carrying cleats to provide traction in the snow. This device suffers from requiring the user to remain in a seated position. Additionally, Husted only envisions use in a snow environment and is not suitable for other terrain. Moreover, this configuration does not provide for the requisite clearance needed to overcome obstacles. Demonstrating another rear propelled device configuration, U.S. Pat. No. 3,826,323 (Mehne) and U.S. Pat. No. 4,519,470 (Allisio) disclose devices that can be used to propel a skier up modest inclines and slopes. The mechanized means of an endless track provides a limited method to traverse snow and does not provide a solution to overcome the variety of terrain that a user may want to explore. Additionally, these endless track devices or the wheeled skis offer less utility when used in conjunction with skates or similar friction reducing means. Finally, U.S. Pat. No. Design 372,000 (Searles) discloses a motorized pushing device that comprises a single tire. Though this device provides for a user that is wearing skates, Searles requires that the thrust of the device push against the hands of the user. Therefore, even Searles fails to provide an adequate and efficient method of providing the force generated by the motorized pushing device over more than a minimal portion of the body of the user.
The present invention overcomes the shortcomings of the prior art by offering a versatile and efficient propulsion device that may be used in a variety of terrain and with skates, skis, or similar friction reducing means. Though the preferred embodiment can propel at least one user across a variety of surfaces ranging from ice to snow or from mud to moderately rocky terrain, the device is easily adapted to provide propulsion in water. The device comprises a frame that secures the user by either attaching about at least one user""s waist or offering the alternative securing means of a back pack harness that engages at least one user at the shoulder level. The frame provides a fixation point for a motor that is either directly connected or connected via a drive train to a rotatable traction device capable of negotiating the medium of the terrain. This device can safely propel each user over a variety of terrains while offering better power and versatility.